The present invention relates to valves and pertains particularly to an improved adjustable pressure check valve.
Check valves are widely used to prevent back flow in a fluid system. This also prevents lines of the system from draining. They are also used to prevent flow until a certain minimum line pressure is achieved.
Some fluid systems may employ several check valves of different pressure settings. For example, some irrigation systems may have sprinkler units positioned at different elevations. This may require check valves for controlling pressure at the different elevations in order to obtain uniform flow rates at the different elevations.
It is preferable that check valves be adjustable in order to avoid the necessity of stocking many different valves. While adjustable check valves are known, they require removal from the system for access to both inlets and outlets thereof for adjustment.
It is desirable that a simple and easily adjustable check valve be available.